Adsorption of phthalic and salicylic acids by two variable charge soils, Haplic Acrisol and Rhodic Ferralsol, was investigated in this study.Results show that both soils were high in adsorption capacity for two organic acids and higher in affinity for phthalic acid.The quantities of the two organic acids adsorbed by Rhodic Ferralsol were larger than by Haplic Acrisol and this result consisted with the content of iron and aluminum oxides in the two soils.The iron oxides in these soils played a significant role in the adsorption of organic acids, but the soil minerals such as kaolinite showed a small adsorption capacity for organic acids.The adsorption of organic acids involved two mechanisms: specific adsorption and electrostatic attraction, but the former was the major one for the two organic acids.Little effect of pH on adsorption of the organic acids was observed below pH4.5, whilst the adsorption decreased with the increase in pH beyond pH4 5.